Attachment for leveiing-instrusvients and transits



(No Model,)

F. PARSON.

ATTACHMENT FOR LEVELING INSTRUMENTS AND TRANSITS No. 331,433. Patented'De-c. 1, 1885..

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FRANK PARSON, OF BATON, TERRITORY OF NEW MEXICO.

SPECIFICATION forming part of Letters Patent No. 331,433, dated December 1, 1885.

Application filed March 14, 1885. Serial No. 158,020. (No model.)

To all whom it may concern:

Be it known that I, FRANK PARSON, a citizen of the United States, residing at Baton, in the county of Colfax and Territory of New Mexico, have invented a new and useful improvement in Surveyors Transits and Levels, of which the following is a specification.

Surveyors at work bring their instruments to a level by means of four thumb-screws. The upper plate with the level-bulbs is moved so that the line of the level-bulb is parallel to one set of screws. Then these screws are worked until the bubble is in center of bulb. So with the other set of screws. The setting of the bulb so as to be parallel to the line of the pair of screws is done by judgment of eye, and is liable to inaccuracy, especially with beginners, so that the process has to be repeated usually several times before the plate is perfectly level.

The object of my invention is to render perfectly precise and accurate the placing of the bulb-line parallel to the screw-line, thus saving time in the leveling of instruments. The annexed drawings illustrate the manner in which I attain this object.

Figure 1 is a perspective of alevel. Fig. 4 is aperspective of a transit. Figs. 2, 3, 5, 6 show details.

P, Fig. 1, is a little metal flattened sharppointed rod, screwed at s to the thumb-screw standard, and pointed at z, where there is a mark on the level-bar. \Vhen the telescope is turned so that z covers said mark, the bulb T is just exactly parallel to the line of the thumb screws 6 e. The same with the other line of thumb-screws, there being a rod like P at every screw.

B and H show another form, less liableto be knocked or injured. This form is in two parts-11, screwed at m; B, fastened atL to the thumb-screw standard.

Fig. 2 represents a face view, Fig. 3 a side view, of these pieces. Theyare made of such length as just to clear each other when the Fig. 4. WVhen z is on lower telescopeisturned, with thin edges wherethey meet, so it may be plainly seen when they are precisely together.

Fig. 4. shows the precision attachment applied to a transit; P, a single rod screwed at 8, pointed at top. When point is brought 5o opposite the mark m on upper plate, the bulb T is exactly parallel to the line of the thumbscrews 6 e. A much better form of -the indicator for the transit is that shown by B and H in two parts, one set for each thumb-screw. H is screwed. to upper plate at x, B screwed to thumb-screw standard.

Fig. 5 shows face view, and Fig. 6 side View, of B and H. The length of course varies with the instrument.

When the tangent-screw 2, Fig. 4, is attached to the upper plate, as is usually the case, the pieces are very easily adjusted, as in plate, the pieces H must be curved out, so as to clear 2.

I claim as my invention, which I desire to secure by Letters Patent-- 1. In a surveyors transit or level, the rod P, secured to the leveling-plate at s', and curved upward and outward to register with a mark on the upper part of instrument, whereby parallelism between the leveling-screws and the level-bubbles may be attained.

2. In a surveyors transit or level, the rod B, secured to theleveling-plate,combined with the rod H, secured to the upper part of the instrument, said rods being so placed on the instrument that when the edged or pointed extremity of one registers with the edged or pointed extremity of the other parallelism between the leveling-screws and the level-bubbles of the instrument will subsist, substantially as described.

FRANK PARSON.

WVitnesses:

G. W. J OY, H. W. Donen. 

